PRIOR CONCURRENT THERAPY: Biologic therapy: See Disease Characteristics At least 4 weeks since prior immunotherapy Chemotherapy: Prior intravesical chemotherapy allowed At least 4 weeks since prior chemotherapy Endocrine therapy: Not specified Radiotherapy: At least 4 weeks since prior radiotherapy No prior radiotherapy to bladder Surgery: See Disease Characteristics At least 2 weeks since prior transurethral resection of the bladder/bladder biopsy